KC03 - EW Terminology

Question 1

Define the following: Signal Bandwidth

Answer 1

The difference between upper and lower frequency limits of a band containing the useful components of a signal

Question 2

List the Effects of Noise

Answer 2

• Masks weak signals
• Degrades sensitivity
• Can result in false targets.

Question 3

State the relationship between thermal noise, temperature and bandwidth

Answer 3

Thermal Agitation Noise

• Produced by molecular agitation in circuitry
• Proportional to temperature and bandwidth as seen in the formula to the right
• Randomly occurring.

Question 4

Define the following: Sensitivity

Answer 4

Minimum detectable signal level (MDS) or Smin.

Question 5

Apply the units of dB to EM theory.

Answer 5

Number = db
0.001 = -30
0.01 = -20
0.1 = -10
1 = 0
10 = 10
100 = 20
1000 = 30
10,000 = 40
100,000 = 50
1,000,000 = 60
10,000,000 = 70

Question 6

Define the following: Noise

Answer 6

Any unwanted signal.

Question 7

Define the following: Gain

Answer 7

• Receiver sets the gain to “best” see returns
• Constant False Alarm Rate.

Question 8

Define the following: Signal to Noise Ratio (SNR)

Answer 8

The ratio of the signal power to the noise power.

S/N = Signal PWR / Noise PWR